题目

In my family, grandfather drinks______ milk, but______ tea.         A. the least; the most    B. the least; the least          C. the most; the most   D. the most; the less 答案：A亚硝酸钠有咸味，外形与食盐相似．但亚硝酸钠对人体健康害，其水溶液显碱性，而食盐的水溶液显中性．根据以上文字的叙述，鉴别亚硝酸钠溶液和食盐溶液应选用的试剂为（ ）A．蓝色石蕊试液B．无色酚酞试液C．食醋D．汽水